The present invention relates to the art of gas separation. It finds particular application in the separation of oxygen from atmospheric air for supply to welding or other downstream equipment at relatively high pressures. It is to be appreciated, however, that the application is also applicable to systems for separating and supplying one or more selected gases, e.g. separating nitrogen from air, membrane separation, hydrolysis, peroxide reduction, or the like.
Heretofore, oxygen separation equipment commonly included a compressor for supplying atmospheric air at a superatmospheric pressure. A crossover valve alternately channeled the atmospheric air to one of a pair of beds filled with a physical separation medium. As one bed passed the oxygen component and retained the other components of atmospheric air, a fraction of the separated oxygen was fed back to the other bed flushing the retained components to rejuvenate the other bed. The pressurized atmospheric air was alternately supplied to each bed as the other bed was rejuvenated to maintain a continuing supply of oxygen or oxygen-rich gas.
Such oxygen separators have been used in automotive garages and other industrial applications to supply oxygen for welding and other industrial equipment. One drawback of the prior arts system resided in sizing the system for the shop. The oxygen separation system needed to be sized to the peak oxygen demand rate, i.e. the system was oversized for non-peak demand periods. The oversizing increased the purchase cost, operating costs, and maintenance costs.
It was difficult to select the size of a system properly for a shop switching from bottled oxygen. Many shop owners could calculate the daily oxygen volume requirements from the number of oxygen tanks purchased. However, such shops rarely had the data from which to calculate the peak oxygen usage rate.
Moreover, even an oversized oxygen separator supplied oxygen or oxygen-rich gas at a relatively low pressure, normally below 60 psi, i.e. many times less than the 2200 psi pressure of bottled oxygen. This relatively low oxygen pressure created a lazy welding flame with little momentum. Although the low momentum flames were adequate for cutting and welding lighter gauges of sheet steel, heavier steel plates and castings required a higher momentum flame.
In accordance with the present invention, a new and improved gas separation system is provided which overcomes the above referenced problems and others.